Automatically locking control mechanism for variable escapement typewriters



May 29, 1956 A. RIX

AUTOMATICALLY LOCKING CONTROL MECHANISM FOR VARIABLE ESCAPEMENT TYPEWRITERS 3 Sheets-Sheet 1 Filed Jan. 27, 1955 May 29, 1956 Filed Jan. 27, 1955 A. RIX 2,747,716 AUTOMATICALLY LOCKING CONTROL MECHANISM FOR VARIABLE ESCAPEMENT TYPEWRITERS 3 Sheets-Sheet 2 w W M.

A. RIX AUTOMATICALLY LOCKING CONTROL MECHANISM May 29, 1956 2,747,716

FOR VARIABLE ESCAPEMENT TYPEWRITERS 5 Sheets-Sheet 3 Filed Jan. 27, 1955 Fig.2

I Z k 3 0.: 2 H 2 8 A 6 7 a I a: 2 v w fi 4. 0 g g 2 I 6 5 5 4 3 2 u n 5,. n .w a 7 4 Z 1 z 3 United States Patent AUTOMATICALLY LOCKING CONTROL MECH- ANISM lOR VARIABLE ESCAPEMENT I YPE- WRITER Albert Rix, Wilhelmshaven, Germany, assignor to Olympia Werke Aktiengesellschaft, Wilhelmshaven, Germany Application January 27, 1955, Serial No. 484,523

Claims priority, application Germany January 27, 1954 4 Claims. (Cl. 197--84) This invention relates to a typewriter with an adjustable escapement, and more particularly to control mechanism for the adjustment of a known type of escapement to provide either the normal single step movement or a double step movement of the paper carriage.

A prior typewriter provided with an adjustable escapement was equipped with a control key which was depressed to change from a normal single step escapement to a double step escapement but it was necessary to tilt the key backwards to lock it in actuated position. This prior arrangement had the disadvantage that the two successive movements of pressing the control key down and tilting it backwards deviated from the normal typing rhythm and thereby influenced the typing speed in an unfavorable manner. Furthermore, the operation of the control key required a certain amount of attention to insure the locking of the mechanism in its double space position.

Objects of the present invention are to provide a control mechanism for a variable escapement typewriter which avoids the disadvantages of the prior constructions. Objects are to provide a control mechanism of the type stated which is automatically locked in actuated positi'on. simply by depressing the same, and which is unlocked and returned to normal position by depressing the same a second time. More specifically, an object is to provide a. control mechanism in which a key-actuated control lever forms a vertically movable member of a four-bar linkage, one bar of the linkage being a slide element which locks the control mechanism in actuated position upon a first depression of the control key and unlocks the mechanism for a spring return to normal position upon a second depression of the control key.

These and other objects and the advantages of the invention will be apparent from the following specification when taken with the accompanying drawings in which:

Fig. l is a fragmentary vertical section through atypewriter having an escapement control mechanism embodying the invention;

Fig. la is a fragmentary perspective view of the control key and associated mechanism for locking the same in depressed or actuated position;

Fig. lb is a fragmentary horizontal section, on a larger scale, on line 1b--1b of Fig. 1;

Fig. 2 is a fragmentary vertical section showing the control key and associated elements in normal nonactuated position;

Fig. 3 is a similar fragmentary vertical section but showing the control key depressed to adjust the escapement mechanism for a double step movement;

Fig. 4 is a similar fragmentary vertical section showing the control key locked in actuated position but raised to the limit of its locked position in preparation for a sec and depression; and

Fig. 5 is a similar fragmentary vertical section showing the control key and associated elements at the instant of unlocking of the mechanism upon a second depression of the control key.

2,747,716 Patented May 29, 1956 In Fig. 1 of the drawings, the reference numeral 1 identifies the frame of a typewriter having a carriage 2 provided with a platen or paper roll 3. The key levers, not shown, are guided by the key lever suspension 4 in the usual manner and are connected by tie-rods 5 to the secondary levers 6 each of which has an arm 6a connected to its type bar, not shown, by a tie-rod 7, and a second arm 61) with a rear end positioned under the uni versal bar 8. The secondary levers 6 are all pivotally supported on a transverse bearing bar 6c in known manner. Mounted on each side wall of frame 1 is a bracket 9 through which bolts 10 are passed to support auxiliary brackets 11 that provide a rotatable support for a shaft 12. A. yoke 13 is secured to shaft 12 by a bolt 13, with the arm 13a of the yoke projecting forwardly and upwardly and provided with a slot 13b, see Fig. lb. Also rigidly secured to shaft 12 is a bell-crank lever having an arm 12a connected to a bracket 11 by a tension spring 12b and an arm 12c projecting radially from the shaft 12 to extend through an opening in a bar 14 which, when depressed into the position shown in dotted lines in Fig. 1, adjusts a sliding pawl of the carriage escapement mechanism, not shown, for a two-step advance of the carriage on each striking of a type key. The bar 14 is normally held in raised position, as shown in full line in Fig. l, by the spring 12b, thereby conditioning the escapernent mechanism pawl for a single step advance of the paper carriage.

A bracket or arm 15 is secured to one end of the universal bar 8 and has a pin 15a fixed in its upper end to provide a pivotal support for a control rod 16 having a shoulder 16a at its rearward end which fits within the slot 13b of the yoke 13.. A pin 17 is fixed to the side wall of frame 1 to support a lever 13 having a rearward arm provided with a slot 18a into which is hooked the end of a pull wire 19 whose lower end extends through control rod 16 to hold the latter normally in elevated position, as shown in Fig. l, with its shoulder 16a spaced above the base of slot 13b of yoke 13. In this position of lever 18, the oscillation of universal bar 8 by the secondary levers 6 moves the rear end of the control rod 16 freely inthe slot 13b of yoke 13 without effecting any actuation of the yoke 13 and shaft 12. The lower part of the lever 18 is connected by a wire 20 with the escapement control mechanism which, in accordance with the invention, moves the wire 20 in the direction of arrow A to turn the lever 18 counterclockwise, thereby permitting pull wire 19 to drop of its own weight and lower control rod 16 into position for its shoulder to engage yoke 13 to turn shaft 12 counterclockwise, thereby tolower the rail 14 to condition the escapement for a two-step advance of the paper carriage.

The control lever 21 of the escapement control mechanism carries a key 22 of conventional shape and is one element of a four-bar linkage which includes a link 23, lever 24, and locking slide 25. The linkage elements are stamped from sheet metal and link 23 is offset rearwardly of its pin connection 26 to lever 21 to pass through the same guide slot 4b of the key lever suspension 4 as the rearward extension 21:: of control lever 21. The rear end of link 23 is hinged by a pin 27 on a bracket 4:: secured to the transverse bar support 4b of the key lever suspension 4. Control lever 21 is connected to lever 24 by a pivot pin 28, and is pivoted on a pin 2h supported on a bracket 6d secured to the transverse bearing bar 60. The rearward portion 24a of lever 24 is provided with a pin 30 to which the forward end of wire 20 is connected, see Fig. l, and a pin 31 which extends through a slot 2511 at the rear end of the locking slide 25. The forward end of the locking slide 25 extends through a slot 40 of key lever suspension 4 which guides it for substantially horizontal reciprocation, and a spring 32 is connected between an intermediate lug 25b of slide 25 and the tip 24b of lever 24 to urge the forward end of the slide upwardly in the slot 4c. Below the lug 25b, the slide 25 is provided with a pair of forwardly bent cars 2550 for cooperation with a laterally bent unlocking flange 21th at the rear end of the extension 21a of the control lever 21. The forward end of the slide 25 has an upward extension 25d which moves in front of the key lever suspension 4 upon depression of the control lever 21. The forward sides of control lever 21 and lever 24 have extensions 21c, 24c between which tension spring 33 is connected to urge control lever 21 toward non-actuated position, and this extension 24c of lever 24 extends through a guide slot 4d in the key lever suspension 4.

As shown in full line in Fig. l, the apparatus is conditioned for a normal single-step advance of the paper carriage upon the striking of any of the type keys, and the control lever is in elevated position as shown in Fig. 2. Upon depressing control key 22, the control mechanism elements assume the positions shown in Fig. 3, i. e. control lever 21 moves downwardly to tilt lever 24 about its pivot pin 29, whereby wire is moved in the direction of arrow A to rock lever 18 and permit control rod 16 to drop into position to engage yoke 13 upon the rocking of universal bar 8 by the actuation of type lever. The tilting of lever 24 moves its pin 31 forwardly to advance the locking slide to position its upward extension 25d in front of the key lever suspension4, see Fig. 3. Spring 32 rocks the slide 25 counterclockwise about pin 31, thereby trapping the extension 2511 in front of the key lever suspension 4 to lock the control mechanism in actuated I in combination with ,a key lever suspension provided position with control key 22 and control lever 21 partially but not fully depressed to the limit permitted by movement of the extension 21a of lever 21 in its guide slot 4b, see Fig. 4. This locks the escapement control mechanismfor a two-step advance of the paper carriage for each typed letter until the control key is again fully depressed,

about pivot pin 26 of link 23 as an axis, and its unlocking I flange 21b engages the ears 25c of locking slide 25 to rock the same clockwise into unlocked position, see Fig. 5. Spring 33 then restores the control linkage to normal non-actuated condition as shown in Figs. 1 and 2, and spring 1212 rocks the shaft 12, whereby arm 12c returns the bar 14 to normal raised position.

While the key actuated control mechanism has been illustrated and described with reference to a control of the carriage escapement, it is to be understood that it is useful in other connections, for example as a control for the carriage shift to write upper case letters.

I claim:

1. In a typewriter, an automatically locking key actuated control mechanism comprising a key-actuated lever, a second lever to which said key-actuated lever is pivoted, means supporting said key-actuated lever for substantially vertical movement, a control member connected to and movable by said second lever from a normal to an actuated position upon a depression of said key-actuated lever, locking means movable by said second lever into locked position upon a first depression of said key-actuated lever, thereby to lock said control mechanism in actuated position, and means on said key-actuated lever for unlocking said locking means upon a second depression thereof.

2. In a typewriter, the invention as recited in claim 1, wherein said supporting means comprises a pivoted link and said key-actuated lever has a rearward extension, in combination with a key lever suspension having a slot through which said link and said rearward extension pass and are guided.

3. In a typewriter, the invention as recited in claim 2, wherein said key lever suspension is provided with a further guide slot and constitutes an element of said locking means, the cooperating element being a slide having a forward end movable in said further guide slot and provided with an upward extension, the rear end of said slide being provided with a slot, a pin on the rear end of said second lever and seated in the slot of said slide, and spring means tilting the forward end of said slide upwardly to trap the upward extension of said slide in front of said key lever suspension upon forward movement thereof by the pin on said second lever.

4. In a typewriter, the invention as recited in claim 1,

with guide slots, and wherein said locking means comprises a slide having a pin and slot connection to said second lever, said slide having a forward end slidable in one of said guide slots, an upward extension on the forward end of said slide and movable by said second lever to a position in front of said key lever suspension, and spring means urging the forward end of said slide upwardly thereby to lock said slide against return movement, and said key-actuated lever has a rearward extension movable in one of said guide slots and said unlocking means comprises a flange on said rearward extension for engagement with the forward end of said slide to move the latter downwardly into unlocked position upon a second depression of said key-actuated lever.

References Cited inthe file of this patent UNITED STATES PATENTS 

